FPU Saving/Restoring Review

Function Code:
src/kernel/include/fpu.h
src/kernel/fpu.c

Test Component:
src/components/implementations/no_interface/fpu/f.c

Changed Files:
src/kernel/thread.c (line 98, 99)
src/kernel/inv.c (line 874)        /* saving/restoring when thread switch*/
src/platform/linux/module/hijack.c (line 727, 1505 1185...1206) /* saving/restoring when interrupt and initialization */